WASHINGTON, June 4 (Reuters) - The U.S. Supreme Court on Wednesday declined to block a court ruling that allowed gay marriage to go ahead in Oregon.

The court turned down without comment an emergency application to suspend the ruling, filed by a conservative group, the National Organization for Marriage, which opposes same-sex marriage.

On May 19, a federal judge struck down the state's gay marriage ban. State officials accepted the ruling and declined to appeal. The ruling went into effect immediately, allowing gay and lesbian couples to marry.

The National Organization for Marriage was not a party in the case. It asked the high court to suspend the lower court's ruling so it could litigate whether it could intervene.